Good evening,
I have to run five pieces of 12-2 nm through a 8″ concrete foundation wall to the new addition. I have a sds bit to drill a 1″ hole. My question is, do I have to put any kind of conduit in these holes to protect the wire or can they pass through the concrete? If I need conduit I was thinking of using pvc so I could ease the edges and hopefully get two pieces per hole.
Just a bit more info: The wires are passing from an interior space to an interior space. This is just about the only route for these wires with out some major work.
Thanks
Todd
Edited 9/21/2004 6:22 pm ET by tmiltier
Replies
Todd,
Your runs can pass through a drilled hole in concrete,they just can't be imbedded in mortar or concrete.
Barry
Thank you Barry. Time to start drilling.
Todd
As much as possible try not to closely bundle the cables before and after the hole. Up to 2", inclusive of the hole, is OK by code but try to keep even this to a minimum. The cables separated can 'breath', be cooled by the air. About 1/2" space between every two cables is sufficient but you can give them more room if you like.
If possible drill a large enough hole for some space around the cables. This also allows some duct seal, or if needed, fire caulk, to be seal the area around the cables. This also keeps the critters out.
Try to round over the edges of your hole to prevent wear on the cables and route the cables with enough slack to allow the cables to sweep gracefully into and out of the hole. I see cables run stretch tight sometimes. This can lead to abrasion and wear.
Common sense but I include this for the less knowledgeable people who may read it. The interior of the hole should be smooth with no burrs, edges or projections.
This isn't my thread, but your response made me think of related question.
what are the rules or rules of thumb for number of romex cables through single holes in 2x studs? I guess the most typical sizes would be 14/2, 12/2, 14/3, and 12/3.
how about radii coming through holes and changing direction?